Release liner for pressure sensitive adhesives and method of use

ABSTRACT

A double-sided adhesive tape assembly that includes a double-sided tape having a pressure sensitive adhesive (“PSA”) on each side thereof and a delaminatable release liner in contact with the pressure sensitive adhesive (“PSA”) on one or both sides of the double-sided tape is disclosed. A roll of the double-sided adhesive tape assembly is also disclosed. Methods of making and using the double-sided adhesive tape assembly are also disclosed.

FIELD OF THE INVENTION

This invention relates to release liners. In particular, the presentinvention relates to release liners for supporting double-sided pressuresensitive adhesive tapes, sheets, etc. that are rolled-up before beingdispensed. More particularly, this invention relates to such releaseliners that can be readily delaminated or otherwise separated into atleast two layers. The present invention also relates to methods of usingsuch release liners.

BACKGROUND

Adhesive tapes have been useful in a variety of industrial andautomotive applications. Double sided adhesive tapes have been used tobond together a variety of substrates or surfaces and are particularlyuseful for industrial and automotive applications. Double-sided adhesivetapes having a pressure sensitive adhesive (PSA) on both sides (e.g., inthe form of a foam core with a pressure sensitive adhesive on each side)have been found useful in bonding together substrates of similar ordissimilar materials

Such double-sided attachment tapes are typically manufactured in widesheets, laminated onto a release liner of matching width to form anadhesive sheet assembly, and then wound into a roll. The resulting wideadhesive roll assembly is then converted or separated (e.g., byslitting) into a plurality of narrower rolls of tape assembly having thesame width or varying widths, depending on the intended use(s) of theadhesive tape.

There is a continuing need for improvements to such double-sidedadhesive tape assemblies. The present invention is such an improvement.

SUMMARY OF THE INVENTION

The present invention is directed to an adhesive tape assemblycomprising a double-sided adhesive tape having a pressure sensitiveadhesive (“PSA”) on each side thereof, and a delaminatable release linerattached to one or both outer adhesive surfaces of the double-sidedadhesive tape. The adhesive tape assembly is capable of forming a rollof tape having superior roll stability (i.e., the rolls are less likelyto fall apart when the roll is held suspended along its outercircumferential edge) compared to double coated tape rolls having twoliners. In this way, the present invention satisfies the need for morestable rolls, especially more stable narrow planetary rolls of a tapeassembly comprising a double-sided tape with a PSA on each side. Thepresent invention also provides a double-sided PSA tape assembly thatincludes a delaminatable release liner, portions of which may be easilyand efficiently removed in a step-wise order to apply the adhesive tapeto one or more substrates.

In one aspect of the present invention, an exemplary adhesive tapeassembly comprises a double-sided adhesive tape comprising front andback adhesive sides, each of the adhesive sides comprising a pressuresensitive adhesive; and a delaminatable release liner in contact with,bonded to and readily removable from at least one of the adhesive sides,the delaminatable release liner comprising a first major release surfaceon an exposed side of the release liner, a second major release surfaceon an opposite side of the release liner, and a plane of weaknessbetween the first and second major release surfaces, wherein the releaseliner can be readily delaminated lengthwise along the plane of weakness,between the first and second major release surfaces, so as to form afirst delaminated layer and a second delaminated layer, with the firstdelaminated layer comprising the first major release surface and a firstback side surface opposite the first major release surface, and thesecond delaminated layer comprising the second major release surface anda second back side surface opposite the second major release surface;wherein the adhesive tape assembly has (i) a first bond strength betweenthe first back side surface and the second back side surface, and (iii)a second bond strength between the first major release surface and thefront adhesive side, and wherein the second bond strength is lower thanthe first bond strength.

In a further aspect of the present invention, an exemplary adhesive tapeassembly comprises double-sided adhesive tape comprising front and backadhesive sides, wherein each of the adhesive sides comprises a pressuresensitive adhesive; a substrate, wherein the front adhesive side of thedouble-sided adhesive tape is permanently bonded to a surface of thesubstrate; and a delaminatable release liner in contact with, bonded toand readily removable from the back adhesive side of the double-sidedadhesive tape, the delaminatable release liner comprising a first majorrelease surface on one side of the release liner, a second major releasesurface on an opposite side of the release liner, and a plane ofweakness between the first and second major release surfaces, whereinthe release liner can be readily delaminated lengthwise along the planeof weakness, between the first and second major release surfaces, so asto form a first delaminated layer and a second delaminated layer, withthe first delaminated layer comprising the first major release surfaceand a first back side surface opposite the first major release surface,and the second delaminated layer comprising the second major releasesurface and a second back side surface opposite the second major releasesurface, wherein the second major release surface is in contact with,bonded to and readily removable from the back adhesive side, and thefirst major release surface is exposed.

The double-sided adhesive tape comprises front and back adhesive sides,with each of the adhesive sides comprising an acrylic or other suitablepressure sensitive adhesive (PSA). The adhesive tape can furthercomprise an acrylic or other suitable foam core with the front adhesiveside and the back adhesive side forming opposite sides thereof. Each ofthe first backing layer and the second backing layer has a releasematerial thereon in the form, for example, of an extruded or laminatedlayer or a coating in contact with, bonded to and readily removable fromat least one of the adhesive sides of the tape.

The adhesive tape assembly may further include a tab heat bonded orotherwise adhered to at least one of the first and second backing layersupon separation of the first backing layer from the second backing layeror vice versa. Each tab is operatively adapted (e.g., dimensioned) tofacilitate removal of the backing layer it is bonded to from theadhesive tape by pulling on the tab.

The adhesive tape assembly can have a width and be wound into a roll,with both release layers (i.e., the first and second release layers) ofthe delaminatable release liner contacting the outer adhesive surfacesof the adhesive tape with the resulting roll having an outercircumferential edge. As a result of the present invention, the diameterof the roll can be, for example, at least about 20 times the width ofthe roll, and the roll not fall apart when held suspended along theouter circumferential edge.

In another aspect of the present invention, a method is provided forpermanently adhering or otherwise applying a double-sided pressuresensitive adhesive tape to one or more surfaces such as, for example, asurface on a product such as, e.g., an interior or exterior bodymolding, a window pane, etc. that is to be adhered to a surface on avehicle (e.g., a body part of an automobile, aircraft, watercraft, etc.)or a building, and other separate surfaces on opposing substrates, etc.The method comprises providing an adhesive tape assembly like thatdescribed above and herein; exposing the pressure sensitive adhesive ofan adhesive side (e.g., by unwinding the adhesive tape assembly) along alength of the adhesive tape assembly; and applying, typically so as topermanently adhere, the exposed pressure sensitive adhesive of theadhesive side of each length of the adhesive tape assembly to a firstsubstrate with the delaminatable release liner positioned over theunexposed pressure sensitive adhesive of the other adhesive side.

It is often desirable for the adhesive tape assembly being provided tobe in the form of a planetary or other desired roll. When the tapeassembly is provided in roll form, the method comprises unwinding theroll to expose the pressure sensitive adhesive of an adhesive side ofthe adhesive tape assembly, optionally cutting the adhesive tapeassembly into discrete sections of desired lengths, and then applyingthe adhesive tape assembly to a first substrate as described above. Eachof the discrete lengths can have a length and a width suitable foradhering a component onto a vehicle, building or other substrate.

The method can further comprise removing at least a portion of an outerportion of the delaminatable release liner (i.e., the first or seconddelaminated layer) on the one or more lengths of the adhesive tapeassembly so as to expose a previously unexposed back side surface of aninner portion (i.e., the second or first delaminated layer) of thedelaminatable release liner previously in contact with, bonded to andreadily removable from the outer portion. Removing the outer portion ofthe delaminatable release liner results in an article assemblycomprising the first substrate having thereon the adhesive tape coveredby an inner portion (i.e., the second or first delaminated layer) of thedelaminatable release liner. The article assembly may be furtherprocessed (e.g., painted) prior to removal of the inner portion of thedelaminatable release liner, and then subsequently bonded to a secondsubstrate by removing the inner portion of the delaminatable releaseliner and bringing the second substrate into contact with the exposedpressure sensitive adhesive surface on the other adhesive side of eachlength of the adhesive tape assembly; and applying, typically so as topermanently adhere, the exposed pressure sensitive adhesive of the otheradhesive side of each length of the adhesive tape assembly to a secondsubstrate. In this way, the adhesive tape is applied between, typicallyso as to permanently adhere together, the first substrate and secondsubstrate.

To make it easier to remove the inner portion (i.e., the second or firstdelaminated layer) of the delaminatable release liner from the adhesivetape, the present method can further comprise heat bonding or otherwiseadhering a tab to the back side surface of the inner portion (i.e., thesecond or first delaminated layer) of the delaminatable release lineralong one or more lengths of the adhesive tape assembly. The tab isadhered sufficiently so as not to detach from the inner portion of thedelaminatable release liner before at least a portion of the innerportion of the delaminatable release liner is pulled off of the adhesivetape. In this way, a tab can be used to at least facilitate the removalof the inner portion of the delaminatable release liner. Before or afterthe outer portion of the delaminatable release liner is removed from theadhesive tape, a tab can be bonded to the inner portion of thedelaminatable release liner on the one or more lengths of the adhesivetape assembly.

Typically, when a tab is bonded to the back side surface of the innerportion of the delaminatable release liner, the outer portion and theinner portion of the delaminatable release liner are removed one afterthe other, rather than at the same time, and are removed only after thefirst exposed adhesive side has been applied, typically so as topermanently adhere, to a first substrate. Thus, the present method canfurther comprise removing the inner portion of the delaminatable releaseliner on the one or more lengths of the adhesive tape assembly bypulling on a tab bonded thereto, so as to expose the other adhesive sideof each length of the adhesive tape assembly; and applying, typically soas to permanently adhere, the exposed pressure sensitive adhesive of theother adhesive side of each length of the adhesive tape assembly to asecond substrate such as, for example, a surface of a vehicle (e.g.,part of an automobile, aircraft or, watercraft), a building, or thelike. In this way, the adhesive tape can be applied between, typicallyso as to permanently adhere together, the first substrate and secondsubstrate.

In one aspect of the present invention, an exemplary method of applyinga double-sided pressure sensitive adhesive tape to one or more surfacescomprises (I) providing an adhesive tape assembly, wherein the adhesivetape assembly comprises a double-sided adhesive tape comprising frontand back adhesive sides, each of the adhesive sides comprising apressure sensitive adhesive; and a delaminatable release liner incontact with, bonded to and readily removable from the back adhesiveside of the double-sided adhesive tape, the delaminatable release linercomprising a first major release surface on one side of the releaseliner, a second major release surface on an opposite side of the releaseliner, and a plane of weakness between the first and second majorrelease surfaces, wherein the release liner can be readily delaminatedlengthwise along the plane of weakness, between the first and secondmajor release surfaces, so as to form a first delaminated layer and asecond delaminated layer, with the first delaminated layer comprisingthe first major release surface and a first back side surface oppositethe first major release surface, and the second delaminated layercomprising the second major release surface and a second back sidesurface opposite the second major release surface, wherein the secondmajor release surface is in contact with, bonded to and readilyremovable from the back adhesive side, and at least a portion of thefirst major release surface is exposed; (II) applying the front adhesiveside of the adhesive tape to a first substrate; (III) at least partiallyremoving the first delaminated layer by separating the first delaminatedlayer from the second delaminated layer; and (IV) bonding a tab to thesecond back side surface of the second delaminated layer, such that thesecond delaminated layer can be removed from the tape by pulling on thetab.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an enlarged cross-sectional view of a portion of one exemplarypressure sensitive adhesive tape assembly according to the presentinvention, with a double-sided pressure sensitive adhesive tapereleasably adhered to a double-sided release liner that can be readilydelaminated into two release layers;

FIG. 2 is a side view of the tape assembly of FIG. 1 in roll form;

FIG. 3 is a top view of the tape assembly of FIG. 1 in roll form;

FIG. 4 is a perspective view of the tape assembly of FIG. 1 in rollform;

FIG. 5 is an enlarged cross-sectioned view of the tape assembly of FIG.1 permanently adhered to a substrate, with a liner removal tab bonded toan exposed surface of an inner portion of the delaminated release linerso as to facilitate the removal of the inner portion of the delaminatedrelease liner from the pressure sensitive tape, according to the presentinvention; and

FIG. 6 is perspective view of a heat bond tabbed tape assembly,according to the present invention, with one PSA layer of the tapeassembly permanently adhered to a substrate.

DETAILED DESCRIPTION OF THE INVENTION

Although the present invention is herein described in terms of specificembodiments, it will be readily apparent to those skilled in this artthat various modifications, rearrangements, and substitutions can bemade without departing from the spirit of the invention. The scope ofthe present invention is thus only limited by the claims appendedhereto.

Referring to FIG. 1, an exemplary delaminatable release liner 11according to the present invention is made with at least twodelaminatable portions 11A and 11B. In exemplary delaminatable releaseliner 11, outer delaminatable portion 11A comprises a first releaselayer 13 and a first backing layer 15. The layers 13 and 15 define afirst major release surface 17 and a first back side surface 19 ofdelaminatable portion 11A, respectively. Inner delaminatable portion 11Bcomprises a second release layer 12 and a second backing layer 14. Thelayers 12 and 14 define a second major release surface 16 and a secondback side surface 18 of delaminatable portion 11B, respectively. Anadhesive tape assembly 20 can be made, according to the presentinvention, by forming delaminatable release liner 11, and releasablybonding delaminatable release liner 11 to an outer adhesive surface 28of a double-sided adhesive tape 22. The tape 22 includes a frontadhesive side or surface 24 defined by a PSA layer 26 of a pressuresensitive adhesive and a back adhesive side or surface 28 defined by aPSA layer 30 of the same or a different pressure sensitive adhesive.Delaminatable release liner 11 is in contact with, bonded to and readilyremovable from PSA layers 30 and 26 when in roll form (see, for example,FIG. 2).

Delaminatable release liner 11 is readily removable from tape 22 suchthat removal of delaminatable release liner 11 or a portion thereof(e.g., outer delaminatable portion 11A, inner delaminatable portion 11B,or both) does not cause significant damage to double-sided adhesive tape22 (i.e., does not cause cohesive failure, substantial tearing orsubstantial permanent stretching of the tape). Typically, it isdesirable for the bond strength between outer delaminatable portion 11Aand inner delaminatable portion 11B to be less than the bond strengthbetween inner delaminatable portion 11B and double-sided adhesive tape22 such that outer delaminatable portion 11A is readily removable frominner delaminatable portion 11B without negatively impacting the bondbetween inner delaminatable portion 11B and double-sided adhesive tape22. Further, it is typically desirable for the bond strength betweenouter delaminatable portion 11A and double-sided adhesive tape 22 (i.e.,surface 24 of tape 22) to be less than the bond strength between outerdelaminatable portion 11A and inner delaminatable portion 11B such that,when in roll form, outer delaminatable portion 11A releasably separatesfrom double-sided adhesive tape 22 (i.e., surface 24 of tape 22) withoutnegatively impacting the bond between outer delaminatable portion 11Aand inner delaminatable portion 11B.

I. Adhesive Tape Assembly Components

As shown in FIG. 1, exemplary adhesive tape assembly 20 may comprise anumber of individual layers. A description of possible layers and layercomponents is provided below.

A. Backing Layers

Adhesive tape assemblies of the present invention comprise adelaminatable release liner such as exemplary delaminatable releaseliner 11 of FIG. 1. Each delaminatable release liner comprises first andsecond backing layers such as first and second backing layers 15 and 14shown in exemplary delaminatable release liner 11 of FIG. 1. Eachbacking layer typically comprises a film or foam material that may beformed from a variety of materials. The composition and structure (e.g.,thickness) of each backing layer is chosen so as to provide sufficienttensile and tear strength to the backing layers so that the backinglayers may be releasably removed from the adhesive tape assembly.Further, the composition and structure (e.g., surface features) of eachbacking layer is chosen so as to provide a desired degree of bondstrength between back side surfaces of the first and second backinglayers (i.e., back side surfaces 19 and 18 of first and second backinglayers 15 and 14 respectively) without the need to chemically modify(i.e., apply a coating) either of the back side surfaces of the firstand second backing layers. This bond strength is referred to herein as a“first bond strength” of the adhesive tape assembly.

Suitable materials for forming first and second backing layers 15 and 14may vary depending on a number of factors including, but not limited to,a desired bond strength between first and second backing layers 15 and14, the thickness of the first and second backing layers 15 and 14,desired release properties of the first and second backing layers 15 and14, and release layer compositions when release layers are subsequentlyapplied onto a major surface of the first and/or second backing layers15 and 14. For example, suitable materials for forming second backinglayer 14 include, but are not limited to, polyesters such aspolyethylene terephthalate (PET); polyolefins such as polypropylene,polyethylene, propylene/ethylene copolymer, polyvinlyl chloride, andTPOs (thermoplastic olefins); any combination thereof; and multilayerfilms or foams containing any combination of the above-describedmaterials, such as a laminate of a thermoplastic polyolefin (TPO) layerand a polyethylene layer.

Suitable materials for forming first backing layer 15 include, but arenot limited to, a polyolefin such as a high density polyethylene, amedium density polyethylene, a low density polyethylene, a linear lowdensity polyethylene, an ultra-low density polyethylene, apolypropylene, a thermoplastic polyolefin (TPO), and an ethylene vinylacetate (EVA) copolymer; a polyester such as polyethylene terephthalate(PET) or a copolyester such as co-polyethylene terephthalate (PET); anycombination thereof; and multilayer films or foams containing anycombination of the above-described materials. High density polyethyleneshave a typical density above about 0.96 g/cc; medium densitypolyethylenes have a typical density in the range from about 0.93 g/ccto about 0.94 g/cc; low density polyethylenes have a typical density inthe range from about 0.90 g/cc to about 0.92 g/cc; and linear low andultra low density polyethylenes have densities below about 0.90 g/cc.The polyethylenes can be made by any method including use ofconventional catalysts as well as metallocene catalysts.

The materials for each layer are selected to provide the desired balanceof bond strengths between the first and second backing layers and thebond strengths between each of the release surfaces and the adhesivesurfaces to which they are respectively bonded to. The selection ofmaterials can be based on the natural affinity that each of materials ofeach layer have for each other as well as the inherent modulus orstiffness of each of the materials, and the processing methods. It isdesirable for the first and second backing layers to have sufficientadhesion to each other so that handling during subsequent processingwill not cause the layers to prematurely delaminate. The amount ofadhesion needed can vary depending upon the handling that occurs inthese processes. For example, in one embodiment, a release liner withfirst and second backing layers may need sufficient adhesion so that astrip of liner measuring about 6 inches by about 24 inches, held undertension by hand, can be twisted about 180 degrees without delaminatingthe two layers.

The adhesion of materials that do not generally adhere well to eachother, i.e., are chemically incompatible, can be increased by blendingsome of the material from one of the layers with the material of theother layer to improve the compatibility of the two materials.Compatible monomers may also be copolymerized with less compatiblemonomers to provide a copolymer layer that can adhere more tightly toanother layer made from a layer of the less compatible monomer alone.For example, low density polyethylene may not adhere sufficiently whenit is extrusion coated onto a layer made of a polymer of polypropylene,but it can adhere sufficiently to a thermoplastic olefin (a copolymer ofpolypropylene and polyethylene) to permit twisting of a strip of therelease liner as described above.

An alternative method to control the bond strength between the layers isto select materials in which the melt temperature of the first backinglayer, which is hot melt coated onto the second layer, is higher thanthe melt temperature of the second backing layer. Heat is needed tocreate a bond between the layers, but the amount of heat to laminate thelayers together is generally not enough to melt both layers. Byselecting one layer to have a lower melt temperature than the other, thelower melt temperature material can be hot melt coated onto the otherlayer without fusing to it. In one embodiment, a melt temperaturedifference of about 30° F. can be used. Other embodiments may have melttemperature differences of about 50° F., 100° F., or more. Embodimentshaving little or no melt temperature differences can be made to bedelaminatable by using chemically incompatible compositions for thelayers or controlling the temperature of lamination of the two layers.

It is desirable for each of the first and second backing layers 15 and14 to have a layer thickness that provides enough tensile and/or tearstrength so that the first and second backing layers 15 and 14 may beremoved from the adhesive tape assembly without tearing the first orsecond backing layer. Typically, each of the first and second backinglayers 15 and 14 has a layer thickness of up to about 50 mils (1.27 mm),and most typically, has a layer thickness ranging from about 1.0 mil (25μm) to about 10 mils (0.25 mm). In one exemplary embodiment of thepresent invention, the first backing layer 15 has a layer thicknessranging from about 1.0 mil (25 μm) to about 5 mils (0.13 mm), while thesecond backing layer 14 has a layer thickness ranging from about 1.0 mil(25 μm) to about 10 mils (0.25 mm). In a further exemplary embodiment,the first backing layer 15 has a layer thickness ranging of about 1.5mil (38 μm), and the second backing layer 14 has a layer thicknessranging of about 5 mils (0.13 mm).

Each of the first and second backing layers 15 and 14 may comprise oneor more of the above-described films or foams with or without furthersurface treatments to alter an outer surface of the film or foam. In onedesired embodiment of the present invention, one or both major outersurfaces of either or both of the first and second backing layers 15 and14 is corona treated so as to provide a surface energy of at least about30 dynes. Corona treatment and other surface treatments suitable for usein the present invention include, but are not limited to surfacetreatments disclosed in U.S. Pat. No. 4,822,451, the disclosure of whichis incorporated herein by reference in its entirety. Such surfacetreatments may be used to enhance (i) surface bonding between firstbacking layer 14 and second backing layer 15 and/or (ii) surface bondingbetween a backing layer and a subsequently applied layer, such as arelease layer described below (e.g., a silicone release material).

Each of the first and second backing layers 15 and 14 comprises a backside major surface (e.g., surface 18 of second backing layer 14 andsurface 19 of first backing layer 15) that is typically in contact with,bonded to and readily removable from the other surface as shown inFIG. 1. As discussed above, the degree of bonding between surface 18 ofsecond backing layer 14 and surface 19 of first backing layer 15 mayvary depending on the materials used to form second backing layer 14 andfirst backing layer 15. Typically, second backing layer 14 and firstbacking layer 15 comprise materials so as to provide a first bondstrength between second backing layer 14 and first backing layer 15 ofat least about 1.0 and up to about 200 g/inch using the 90 Degree PeelAdhesion Test Method described below. In one desired embodiment, secondbacking layer 14 and first backing layer 15 comprise materials so as toprovide a first bond strength between second backing layer 14 and firstbacking layer 15 of at least about 10 g/inch. It is desirable for secondbacking layer 14 and first backing layer 15 to have the above-mentionedfirst bond strength therebetween without the aid of additional surfacetreatments and/or layers between the second backing layer 14 and firstbacking layer 15. In other words, it is desirable for the second backinglayer 14 and first backing layer 15 to have the above-described firstbond strength between surface 18 of second backing layer 14 and surface19 of first backing layer 15.

It is also desirable for surface 18 of second backing layer 14 andsurface 19 of first backing layer 15 to be substantially free ofsilicone release material or any other material that would preventattachment of a tab to the back side surface (i.e., surface 18 and/or19) as described below.

The selection of materials for forming second backing layer 14 and firstbacking layer 15 may also take into account the melting points of thematerials in second backing layer 14 and first backing layer 15. In oneexemplary embodiment of the present invention, the first backing layer15 has a first melting point and the second backing layer has a secondmelting point, wherein the second melting point is at least 10° C. (50°F.) greater than the first melting point. In a further exemplaryembodiment of the present invention, the second melting point is atleast 37.8° C. (100° F.) greater than the first melting point.

In one exemplary embodiment of the present invention, second backinglayer 14 (or first backing layer 15) comprises a heat resistant filmmaterial that can withstand post-formation processing temperatures(i.e., temperatures exposed to during a given application) of up toabout 175° C. Such a construction is desirable when first backing layer15 (or second backing layer 14) is extruded onto second backing layer 14(or first backing layer 15) during the process of preparing exemplarydelaminatable release liner 11. Such a construction is desirable forapplications wherein a heat-bondable tab is bonded to a major outersurface of second backing layer 14 (or first backing layer 15) asdescribed below. Second backing layer 14 and first backing layer 15 mayhave a melting point that varies depending on a given application.Typically, second backing layer 14 has a melting point of at least about130° C., while first backing layer 15 has a melting point of at leastabout 90° C.

In a further exemplary embodiment of the present invention, firstbacking layer 15 comprises a low density polyethylene (LDPE), and secondbacking layer 14 comprises a multilayer structure having three distinctlayers, wherein the three distinct layers comprise first and secondclear outer layers of thermoplastic polyolefin, and an intermediatelayer of thermoplastic polyolefin containing a colorant positionedbetween the first and second clear outer layers. Suitable colorantsinclude, but are not limited to, pigments (e.g., carbon black), dyes, orany combination thereof.

B. Release Layers

The delaminatable release liners may further comprise two majoroutermost release surfaces, typically in the form of release layers suchas release layers 12 and 13 shown in exemplary delaminatable releaseliner 11 of FIG. 1. Release layers 12 and 13 may each comprise anymaterial suitable for functioning as release layers and remainingintegral with their respective backing layers 14 and 15. Each of therelease layers 12 and 13 may comprise release material in the form of acontinuous or discontinuous (e.g., patterned) coating or layer that isintended to contact, bond to and be readily removable from one of thePSA layers of the double-side PSA tape 22. The release material can becoated onto, extruded as part of, laminated as part of, or otherwiseprovided to form surfaces 16 and 17 of release layers 12 and 13respectively.

In another embodiment, materials for first and second backing layers 14and 15 are selected such that they are delaminatable from each other andeach of the layers has outer exposed surfaces 16 and 18 that havesufficient release properties from a double sided pressure sensitiveadhesive tape without requiring separate release layers. For example, arelease liner having a low density polyethylene backing layer and asuitable thermoplastic olefin backing layer can be used with doublecoated tapes having acrylic pressure sensitive adhesives having low tomoderate tackiness.

Suitable release materials include, but are not limited to, polyolefins,silicones, fluorocarbons, low adhesive backsizes (e.g., those made forpolyureas, polyurethanes, polyacrylates, etc.), perfluoroether, andcombinations thereof. General knowledge in the art can be used to helpin the selection of the release material for a certainpressure-sensitive adhesive. For example, a polyacrylate PSA can be usedwith release materials made from polyolefins, silicones, andfluorocarbons. A tackified block copolymer PSA can be used with polyureaor polyurethane backsizes as well as silicones and fluorocarbons.

It can be desirable for the release material of each release layer incontact with a high bond strength pressure sensitive adhesive (describedbelow) to comprise at least one of a silicone and a fluorocarbon, andmay also include a low adhesive backsize, and blends or combinationsthereof, in an effort to ensure that the delaminatable release liner isreadily removable from such a high bond strength PSA. These releasematerials are typically in an amount and of a nature that prevents apolymeric tab, such as that described below and made from a polyamide,PE, PP, EVA, TPO or PE/PP, from being sufficiently heat bondable to arelease side of the delaminatable release liner to consistently allowthe delaminatable release liner to be removed by pulling on the tab(i.e., the tab pulls off before the delaminatable release liner isremoved).

Release layers 12 and 13 may comprise the same release material or maycomprise different release materials. In one exemplary embodiment of thepresent invention, each of release layers 12 and 13 comprise a silicone,a fluorocarbon, a low adhesive backsize, or a blend or combinationthereof. In a further exemplary embodiment, each of release layers 12and 13 comprise a silicone release material. For example, release layer12 may comprise a curable epoxy-silicone component such as aphotocurable cycloaliphatic epoxy functional dimethylsilicone polymercommercially available under the trade designation GE UV9430 from GESilicones (Wilton, Conn.), an epoxy-functional linearpolydimethylsiloxane copolymer commercially available under the tradedesignation GE UV9315 from GE Silicones (Wilton, Conn.), or acombination thereof. Release layer 13 may comprise a silicone resin suchas a silanol terminated polydimethylsiloxane resin commerciallyavailable under the trade designation GELEST DMS S12 from Gelest, Inc.(Morrisville, Pa.).

The degree of bonding between major release surfaces 16 and 17 ofrelease layers 12 and 13 respectively and adjacent adhesive surfaces(i.e., adhesive surfaces 28 and 24) may vary depending on the materialsused to form release layers 12 and 13, as well as the PSAs used to formadhesive layers 26 and 30. As used herein, the term “second bondstrength” is used to refer to the bond strength between the majorrelease surface 17 and front adhesive side 24 of adhesive tape assembly20, while the term “third bond strength” is used to refer to the bondstrength between the major release surface 16 and back adhesive side 28of adhesive tape assembly 20. Typically, release layers 12 and 13comprise materials so as to provide a second bond strength between majorrelease surface 17 and front adhesive side 24 and a third bond strengthbetween major release surface 16 and back adhesive side 28 of at leastabout 5.0 and up to about 200 g/inch using the 90 Degree Peel Adhesiontest. In one desired embodiment, release layers 12 and 13 comprisematerials so as to provide a second bond strength between major releasesurface 17 and front adhesive side 24 and a third bond strength betweenmajor release surface 16 and back adhesive side 28 of at least about 7.0g/inch using the 90 Degree Peel Adhesion test.

It is desirable for second bond strength between first major releasesurface 17 and front adhesive side 24 to be lower than first bondstrength between first back side surface 19 and second back side surface18 so that when adhesive tape assembly 20 is in roll form, frontadhesive side 24 separates from release surface 17 such thatdelaminatable liner 11 is on one side of adhesive tape 22. Further, itis desirable for first bond strength between first back side surface 19and second back side surface 18 to be lower than third bond strengthbetween second major release surface 16 and back adhesive side 28 sothat delaminatable portion 11A can be removed from delaminatable portion11B without negatively impacting the bond between second major releasesurface 16 and back adhesive side 28.

As discussed above, it is desirable for the first bond strength betweenouter delaminatable portion 11A and inner delaminatable portion 11B(i.e., between surface 18 of second backing layer 14 and surface 19 offirst backing layer 15) to be less than the third bond strength betweeninner delaminatable portion 11B (i.e., release surface 16 of releaselayer 12) and double-sided adhesive tape 22 (i.e., adhesive surface 28of adhesive layer 30) such that outer delaminatable portion 11A isreadily removable from inner delaminatable portion 11B withoutnegatively impacting the bond between inner delaminatable portion 11Band double-sided adhesive tape 22. Further, as discussed above, it istypically desirable for the second bond strength between outerdelaminatable portion 11A (i.e., release surface 17 of release layer 13)and double-sided adhesive tape 22 (i.e., surface 24 of tape 22) to beless than the first bond strength between outer delaminatable portion11A and inner delaminatable portion 11B (i.e., between surface 18 ofsecond backing layer 14 and surface 19 of first backing layer 15) suchthat, when in roll form, outer delaminatable portion 11A (i.e., releasesurface 17 of release layer 13) releasably separates from double-sidedadhesive tape 22 (i.e., surface 24 of tape 22) without negativelyimpacting the bond between outer delaminatable portion 11A and innerdelaminatable portion 11B.

In one desired embodiment of the present invention, the third bondstrength between release layer 12 and adjacent PSA layer 30 is at leastabout 10 and up to about 200 g/inch using the 90 degree adhesion test,while the second bond strength between release layer 13 and adjacent PSAlayer 26 is at least about 5.0 and up to about 100 inch using the sametest. The first bond strength in this embodiment can be from about 4 to12 g/inch. While ranges can overlap, each specific embodiment woulddesirably have a second bond strength less than the first bond strength,and the first bond strength less than the third bond strength. Inanother desired embodiment, the second bond strength is between about 6to about 7 g/inch, the first bond strength is between about 10 and about20 g/inch, and the third bond strength is between about 40 and about 60g/inch using the 90 degree adhesion test. In one desired embodiment, thethird bond strength between release layer 12 and adjacent PSA layer 30is about 50 g/inch, the second bond strength between release layer 13and adjacent PSA layer 26 is about 7.0 g/inch, and the first bondstrength between second backing layer 14 and first backing layer 15 isabout 10 g/inch using the 90 degree adhesion test.

C. Optional Intermediate Layers

It can be desirable in some embodiments for either or both ofdelaminatable portions 11A and 11B to include an optional intermediatesupport layer (not shown) disposed between the backing layers 14 and 15and release layers 12 and 13, respectively, to provide additionalstructural support to delaminatable portions 11A and 11B. Suchadditional support can be desirable, for example, in order to facilitateseparation of delaminatable portions 11A and/or 11B from adhesive tape22. By making either or both of delaminatable portions 11A and 11Bstiffer than adhesive tape 22, with the addition of a suitableintermediate layer, it is usually easier to separate delaminatableportions 11A and 11B from adhesive tape 22. The intermediate layer maybe a substantially continuous film, e.g., an extruded or solvent coatedfilm, or may be a web, e.g., a non-woven, knit, woven, or other web,that has one or more holes or perforations therein, such as thatdisclosed in U.S. Pat. No. 5,167,995, which is incorporated herein byreference in its entirety. Satisfactory results can be obtained with anintermediate layer for delaminatable portions 11A and/or 11B comprisinga high density polyethylene (“HDPE”) or a medium density polyethylene(“MDPE”).

D. Adhesive Tape Layers

The above-described delaminatable release liners are suitable for usewith any double-sided pressure-sensitive adhesive (PSA) tape, and areparticularly useful when the PSA tape includes at least one high bondstrength PSA. Examples of such tapes include an adhesive transfer tapethat is a single layer of pressure-sensitive adhesive or a double coatedtape that may or may not include a backing layer between two or morelayers of pressure-sensitive adhesive. The double coated tape may haveonly two layers of pressure-sensitive adhesive adhered to each other toform the tape. The adhesives on each major surface can be the same orthey may be different as might be the case if the adhesives wereformulated to adhere to two substrates together with the substrateshaving different types of surfaces, e.g., a high energy surface such asa metal surface to a low energy surface such as a polyolefin surface.The double coated tape may include an intermediate layer (e.g.,intermediate layer 36 shown in FIG. 1) between the two adhesives. Thislayer may be any suitable structure for a tape backing. Examples of suchstructures include, but are not limited to, a polymeric film, apolymeric foam, a metal foil, a paper, a nonwoven fabric, a wovenfabric, a ceramic woven or nonwoven cloth, and the like. Suitablepolymeric films can include biaxially oriented polyester, biaxiallyoriented polypropylene, mono-axially oriented polypropylene, and thelike. Suitable polymeric foams include polyethylene foams, polyurethanefoams, polyacrylate foams, neoprene foams, and the like.

The present invention contemplates the use of any suitable PSA in thepractice of the invention. PSAs are generally known in the art andinclude, but are not limited to, polyacrylate polymers and copolymers,polyurethanes, ethylene vinyl acetate copolymers, natural rubber, blockcopolymers, and the like. The adhesives may include tackifiers andplasticizers as needed to provide the desired adhesive and modulusproperties for the end use of the tape.

The adhesives may be formed by bulk polymerization, solventpolymerization, emulsion polymerization, etc. and can be cross-linked orleft uncrosslinked. Cross-linking may be accomplished by various meansknown by those skilled in the art such as chemical cross-linking,thermal cross-linking, radiation cross-linking, and combinationsthereof.

The pressure sensitive adhesive for one or both of adhesive layers 26and 30 of exemplary tape 22 can be a high bond strength PSA thatexhibits a bond strength, or requires a removal force, of greater thanabout 30 ounces per inch (336 g/cm) after being bonded to a polyolefinsurface (e.g., a polyolefin like polyethylene, and especially a lowdensity polyethylene), and removed from the polyolefin surface at aremoval rate of about 12 inches per minute (30 cm/min). High bondstrength PSAs can also be characterized as those that exhibit a bondstrength, or require a removal force, of at least about 2.0 pounds perinch (357 g/cm), and in some cases at least about 10.0 lbs./in (1.78Kg/cm), after being bonded to a low density polyethylene (LDPE) surfacefor at least 24 hours and removed from the LDPE surface at a removalrate of about 12 inches per minute (30 cm/min). Such high bond strengthpressure sensitive adhesives can be obtained, for example, using theprocesses and compositions described in PCT Patent Publication No. WO00/06637 (PCT Application No. US 99/17344, filed Jul. 30, 1999) and U.S.Pat. No. 6,103,152, which are both incorporated herein by reference intheir entirety. Other PSAs that may be suitable for use in the adhesivetape of the present inventive tape assembly can be found in PCT PatentPublication No. WO 01/57151 (PCT Application No. 2001/02976, filed Jan.30, 2001), U.S. Pat. No. 6,630,531, and U.S. Published PatentApplication No. 2004/0229000, which are all incorporated herein byreference in their entirety.

In order to make it even easier for a portion of the delaminatablerelease liner (e.g., delaminatable portion 11A) to be removed from a PSAlayer of adhesive tape 22 (e.g., layer 26), and thereby facilitate theprocess of using the remaining tape assembly even further (i.e.,adhesive tape assembly 20 without delaminatable portion 11A), it can bedesirable for the release material to be chosen such that the strengthof the bond between the PSA layer and the adjacent release layer is nomore than about 1.0 oz/in (11.2 g/cm). When the adhesive layer comprisesa high bond strength PSA, like those described above, it is desirable touse a silicone or similar release material in both release layers (e.g.,release layers 12 and 13) of the delaminatable release liner in order toobtain such low liner release forces.

The PSA layer 26 can be supplied on its own release liner andsubsequently bonded to PSA layer 30 (or intermediate layer 36) dependingon the tape construction desired. Alternatively, PSA layer 30 can besimilarly supplied. It can be desirable for at least one of the pressuresensitive adhesive layers 26 and 30 to be readily bondable to surfacesof a wide range of materials including, for example, metal materials,ceramic materials, and/or polymeric materials. Polymeric materials mayinclude thermoset and thermoplastic plastic materials such as, forexample, those used to make automotive exterior trim parts such as bodyside moldings and claddings used on the sides of automobile bodies, aswell as to make other plastic articles. It may also be desirable for atleast one of the pressure sensitive adhesive layers 26 and 30 to bereadily bondable to surfaces of a wide range of thermoset andthermoplastic olefinic elastomers such as, for example, SANTOPRENE(manufactured by Monsanto, St. Louis, Mo.), ethylene propylene dienemonomer (EPDM), polypropylene, high density polyethylene and low densitypolyethylene. An adhesion promoter (e.g., 3M 4298UV Adhesion Promotermanufactured by 3M Company, St. Paul, Minn.) can be used to promote thebonding of the PSA to such elastomeric materials. Elastomeric materialshave been used, for example, to make weatherstrip for sealing automobiledoors and windows, as well as to make other elastomeric articles.

Referring to FIG. 2, adhesive surface 24 of PSA layer 26 contacts firstmajor release surface 17 of first release layer 13 when adhesive tapeassembly 20 is wound into a roll 32. Roll 32 exhibits a desired level ofroll stability due to (1) the bond strength between adhesive surface 24of PSA layer 26 and first release surface 17 of first release layer 13,(2) the bond strength between surface 19 of first backing layer 15 andsurface 18 of second backing layer 14, and (3) the bond strength betweensecond release surface 16 of second release layer 12 and adhesivesurface 28 of PSA layer 30.

Planetary rolls of a double-sided PSA tape assembly having two linersthat are made with a tape having a thickness of at least about 15 milsor more (e.g., typically foam tapes) can be particularly prone to rollinstability problems, because the rolls tend to be larger in diametercompared to tape assemblies with thinner tapes, in order to provide thesame length of tape on a single roll. Such tape assemblies that arenarrow in width can be even more likely to exhibit roll instability. Theadhesive tape assemblies of the present invention are less likely toexhibit roll instability, even when comparable lengths of the tapeassembly are relatively narrow in width and the adhesive tape has athickness of at least about 15 mils or more.

Referring to FIGS. 2-4, when the adhesive tape assembly 20 has anoverall thickness, t, of about 0.052 inches (0.132 cm) and is wound intoa roll 32 having tape end 29, with adhesive surface 24 of PSA layer 26in contact with first release surface 17 of first release layer 13, theroll can exhibit roll stability (i.e., the coils forming the roll 32 donot substantially telescope or fall apart when the roll 32 is heldsuspended along its outer circumferential edge) even when the roll 32has a diameter d that is at least about 20 times the width w of theadhesive tape assembly 20. This is the minimum diameter to width ratioat which roll stability problems have been experienced with rolls ofprior adhesive tape assemblies comprising a double-sided adhesive tape,with a first PSA side and a second PSA side, and a release linerreleasably bonded to each PSA side.

An example of an adhesive tape assembly 20 that can be used to form anarrow roll 32 according to the present invention, has a width w of upto about 1 inch (2.54 cm), a thickness of about 0.052 inches (0.132 cm)and a length in the range of from about 36 yards (33 m) to about 144yards (132 m) and, it is believed, even longer (i.e., a diameter towidth ratio ranging from about 20 to about 70). For many applications,the present adhesive tape assemblies will have a width w of up to about0.5 inches (1.27 cm), a thickness of about 0.052 inches (0.132 cm) and alength in the range of from about 36 yards (33 m) to about 144 yards(132 m) and, it is believed, even longer (i.e., a diameter to widthratio ranging from about 20 to about 70).

E. Optional Tab Component

In some embodiments of the present invention, an optional tab may beattached to a back side surface (e.g., back side surface 18, 19, or both18 and 19) of at least one of backing layers 14 and 15 to facilitateseparation of a portion of the delaminatable liner (e.g., delaminatableportions 11B) from adhesive tape 22 and/or separation of a portion ofthe delaminatable liner (e.g., delaminatable portions 11A) from anotherportion of the delaminatable liner (e.g., delaminatable portions 11B).An exemplary embodiment using a tab is shown in FIG. 5.

As shown in FIG. 5, exemplary adhesive tape assembly 20 is attached tosubstrate 50 such that front adhesive surface 24 is permanently adheredto surface 51 of substrate 50. Delaminatable portion 11A is shown in apartially removed position so that first and second back side surfaces19 and 18 of delaminatable portion 11A and delaminatable portion 11B areexposed. (Although not shown in FIG. 5, a second tab may be attached tofirst back side surface 19 of delaminatable portion 11A prior to orduring formation of delaminatable liner 11 and be used to separatedelaminatable portion 11A from delaminatable portion 11B so as to putdelaminatable portion 11A in the partially removed position as shown.)In this exemplary embodiment, tab 40 is attached to second back sidesurface 18 of delaminatable portion 11B. Typically, tab 40 isheat-bonded to a given back side surface. Once attached, tab 40 can beused to facilitate removal of delaminatable portion 11B from backadhesive surface 28 of adhesive tape 22. As discussed above, secondmajor release surface 16 of delaminatable portion 11B is formulated sothat removal of delaminatable portion 11B does not cause significantdamage to double-sided adhesive tape 22 (i.e., does not cause cohesivefailure, substantial tearing or substantial permanent stretching of thetape).

Tab 40 can comprise at least one of a polyamide, polypropylene,polyethylene, ethylene vinyl acetate, polyester, thermoplasticpolyolefin (TPO), copolymer of polyethylene and polypropylene, andcombinations thereof. Tab 40 is operatively adapted (e.g., dimensionedand formulated) for being heat bonded to second back side surface 18 ofsecond back side layer 14 (or first back side surface 19 of first backside layer 15) so as to allow delaminatable portion 11B (ordelaminatable portion 11A) of delaminatable release liner 11 to beremoved from adhesive tape 22 by pulling on the tab 40 in the directionshown by the arrow in FIG. 5. Such a tab 40 is intended to make iteasier for delaminatable portion 11B (or delaminatable portion 11A) ofdelaminatable release liner 11 to be removed. Suitable materials for tab40, intended to be heat bonded to a PE, PP, TPO or PE/PP second backside layer 14 (or first back side layer 15), can include polyamides,PEs, PPs, TPOs, EVAs, and PE/PPs. Suitable materials for tab 40 intendedto be heat bonded to a PP second back side layer 14 (or first back sidelayer 15) can include polyamides, TPOs, PPs, and PE/PPs. Suitablematerials for tab 40 to be heat bonded to a polyester second back sidelayer 14 (or first back side layer 15) can include polyesters,co-polyesters, polyamides and polyimides.

A tab may also be formed from a tape having a backing coated with asuitable pressure-sensitive adhesive, wherein the pressure-sensitiveadhesive has a sufficient bond strength to the layer of material to beremoved so that when the tab is applied to the surface of the layer andpulled, the appropriate layer separates from the tape assembly. Suitablebacking materials have a tensile strength greater than the bond strengthneeded to remove the layer. Examples of suitable materials includepolyesters, polypropylene, biaxially oriented polypropylene, paper,polyamides, and the like. Pressure-sensitive adhesives can be selectedto bond well to the layer to be removed. Suitable adhesives includeacrylic adhesives, tackified block copolymer adhesives, siliconeadhesives, and the like.

III. Methods of Making Adhesive Tape Assemblies

The adhesive tape assemblies of the present invention can be formed by avariety of conventional process steps. For example, backing layers 14and 15 may be co-extruding to form separatable portion of thedelaminatable release liner. Alternatively, backing layers 14 and 15 canbe formed by extruding one of the layers (e.g., first backing layer 15)onto the other layer (e.g., second backing layer 14) or vice versa. Ineither case conventional commercially available extruders and techniqueswell known in the art can be used. For example, conventional blown filmextrusion equipment and techniques can be used to simultaneouslyco-extrude two or more layers (e.g., layers 14 and 15). Extruders forcetheir corresponding layers through a common die. In this way, thevarious layers can be laminated together simultaneously as they areformed. In blown film extrusion, the laminated layers are extruded intothe form of a tube. The tube is then collapsed, rolled flat and theedges trimmed to form backing layers 14 and 15. Backing layers 14 and 15are then optionally coated with a release layer as described above, andthen subsequently laminated to a double sided adhesive tape 22 to form atape assembly 20. In the case where the release material includessilicone or fluorocarbon, for example, the release material may beapplied as a solvent based coating, a water based coating, or a 100%solids coating (i.e., the solids are in liquid form without a solvent)onto backing layers 14 and 15.

IV. Methods of Using Adhesive Tape Assemblies

The present invention is further directed to methods of using theabove-described adhesive tape assemblies. In one exemplary embodiment, amethod of using an adhesive tape assembly comprises applying adouble-sided pressure sensitive adhesive tape to one or more surfaces,wherein the method comprises (1) providing an adhesive tape assembly,wherein the adhesive tape assembly comprises a double-sided adhesivetape comprising front and back adhesive sides, each of the adhesivesides comprising a pressure sensitive adhesive; and a delaminatablerelease liner in contact with, bonded to and readily removable from theback adhesive side of the double-sided adhesive tape, the delaminatablerelease liner comprising a first major release surface on one side ofthe release liner, a second major release surface on an opposite side ofthe release liner, and a plane of weakness between the first and secondmajor release surfaces, wherein the release liner can be readilydelaminated lengthwise along the plane of weakness, between the firstand second major release surfaces, so as to form a first delaminatedlayer and a second delaminated layer, with the first delaminated layercomprising the first major release surface and a first back side surfaceopposite the first major release surface, and the second delaminatedlayer comprising the second major release surface and a second back sidesurface opposite the second major release surface, wherein the secondmajor release surface is in contact with, bonded to and readilyremovable from the back adhesive side, and at least a portion of thefirst major release surface is exposed; (2) applying the front adhesiveside of the adhesive tape to a first substrate; (3) at least partiallyremoving the first delaminated layer by separating the first delaminatedlayer from the second delaminated layer; and (4) bonding a tab to thesecond back side surface of the second delaminated layer, such that thesecond delaminated layer can be removed from the tape by pulling on thetab.

In the above exemplary method, the adhesive tape assembly may be in rollform (see FIG. 2). When the adhesive tape assembly is in roll form, theabove exemplary method further comprises unwinding the roll to exposethe front adhesive side of the adhesive tape. The above exemplary methodmay further comprise one or more processing steps once the firstdelaminated layer (e.g., delaminatable portion 11A) is removed from thesecond back side surface of the second delaminated layer (e.g.,delaminatable portion 11B), and a tab is attached to the seconddelaminated layer (e.g., delaminatable portion 11B). For example, themethod may further comprise the step of applying paint onto the firstsubstrate and the second back side surface of the second delaminatedlayer. After any optional processing steps, the method may furthercomprise the step of pulling the tab to remove the second delaminatedlayer (e.g., delaminatable portion 11B) from the adhesive tape assemblyto expose the pressure sensitive adhesive of the back adhesive side. Theexposed pressure sensitive adhesive of the back adhesive side may bebrought into contact with a second substrate so that the adhesive tapeis positioned between the first substrate and the second substrate. Inone exemplary embodiment, the first substrate comprises an elastomericarticle, and the second substrate comprises a painted or unpaintedsurface of a vehicle.

A further use of the adhesive tape assemblies of the present inventionis depicted in FIG. 6. Referring to FIG. 6, an article assembly 44 ofthe present invention includes adhesive tape 22 bonded via frontadhesive side 24 to, for example, a plastic or elastomeric article 42(e.g., an automotive exterior trim part, such as body side moldings andcladdings used on the sides of automobile bodies, and the like; aweatherstrip for sealing automobile doors and windows, and the like; aswell as other plastic and elastomeric containing articles), withdelaminatable portion 11B (e.g., second release layer 12 and secondbacking layer 14) being releasably bonded to back adhesive side 28 oftape 22. A tab 40 is bonded to back side surface 18 of second backinglayer 14. It is preferable that back side surface 18 of second backinglayer 14 be substantially free of a release material such as, forexample, silicone that can prevent or at least significantly inhibit thebonding of tab 40 to back side surface 18 of second backing layer 14.The bond between tab 40 and second backing layer 14 should be strongenough to allow delaminatable portion 11B of delaminatable release liner11 to be removed from adhesive tape 22 by pulling on tab 40 in thedirection shown by the arrow in FIG. 6. It can also be preferable forthe back side (i.e., back side surface 19) of first backing layer 15 tobe similarly free of such a release material, especially if a tab 40 isintended to be bonded to back side surface 19 of first backing layer 15.Such a use of a tab 40 (i.e., bonded to back side surface 19 and/or 18)can enable the corresponding delaminatable portion (i.e., delaminatableportion 11A and/or 11B, respectively) to be more easily removed.

FIG. 6 shows article 42 after delaminatable portion 11A of delaminatablerelease liner 11 has been removed from delaminatable portion 11B andseparated from adhesive side 24 of adhesive tape 22. Alternatively, roll32 can be unwound such that back side 28 of adhesive tape 22 is exposed(i.e., first release surface 17 of first release layer 13 is still incontact with front adhesive surface 24 of PSA layer 26 after unwoundingroll 32). In this alternative embodiment, delaminatable portion 11B ofdelaminatable release liner 11 can be removed first after bonding backside 28 of adhesive tape 22 to article 42. With such an application, itmay be desirable to bond a tab 40 to back side surface 19 of firstbacking layer 15 to assist in the removal of delaminatable portion 11Afrom adhesive tape 22 as described above.

EXAMPLES

The following test methods were used in the Examples below.

90 Degree Peel Adhesion Test Method:

A one inch (2.5 cm) wide by 6 inch (15 cm) long sample is cut from asample adhesive tape assembly or from a piece of the liner. The test isperformed at a 90 degree angle using an Instron tensile tester with ajaw separation speed of 12 inches per minute.

Sample Preparation for Liner: The outer surface of second layer 16 islaminated to an anodized aluminum panel having a thickness of about0.127 mm using an acrylic pressure-sensitive adhesive tape and rolleddown with a 6.8 kg metal roller. The first backing layer 15 is separatedfrom second backing layer 14 manually (i.e., with a fingernail or razorblade) to start the delamination. Approximately 2.5 cm of the firstbacking layer is delaminated. The delaminated portion of the backing isplaced in the upper jaw of the tensile tester and the panel ispositioned horizontally in a fixture on the lower jaw. The average peelforce for five test samples is recorded.

Sample Preparation for Tape: A strip of tape is adhered to a 0.127 mmthick anodized aluminum panel and rolled down with a 6.8 kg roller.After allowing the test tape to dwell in contact with the liner for 72hours at room temperature, the panel is positioned in the tensile testeras described above with all of the layers of the release liner clampedtogether in the upper jaw. Linear release was measured as an averagepeel force using an integrated average over 5 seconds test time.

Example 1

A 3-layer thermoplastic olefin (TPO) film was prepared by coextrudingthree layers of TPO (FLEXATHENE™ TP38NC01X01 thermoplastic polyolefinavailable from Equistar Chemicals, LP, Houston, Tex.) on a blown filmextruder. The film had a total thickness of about 5 mils (0.127 mm) withthe middle layer containing a red pigment while the outer layers wereessentially clear. Each of the layers was about 1.5 mils.

A 1 mil (0.025 mm) low density polyethylene (LDPE) film was prepared byextruding LDPE (PETROTHENE™ 951 low density polyethylene available fromEquistar Chemicals, LP, Houston Tex.) on a blown film extruder.

The blown films were converted into flat films and laminated to eachother by extruding 0.5 mil (0.012 mm) LDPE (PETROTHENE™ 951 low densitypolyethylene) onto the 5 mil TPO film and laminating the 1 mil LDPE filmto it using a nip roll. During extrusion, the molten LDPE fuses to theLDPE film while adhering delaminatably to the TPO film. The resultinglaminate is a suitable delaminatable release liner for an acrylicpressure-sensitive adhesive tape such as Acrylic Foam Tape 4220available from 3M Company, St. Paul Minn.

Example 2

The release liner of Example 1 was corona treated to a surface energy ofat least about 30 dynes. A silicone coating prepared according to U.S.Pat. No. 6,835,422, the subject matter which is hereby incorporated byreference in its entirety, was coated onto the polyethylene surface ofthe release liner. The liner is a suitable release liner for astrippable tape.

Example 3

The silicone coated release liner of Example 2 was coated with a UVcurable epoxy silicone release material. The composition contained 40parts UV9430 epoxy silicone, 60 parts UV9315 epoxy silicone, and 2 partsof UV9380C Photocatalyst. All of the components are available from GESilicones, Waterford, N.Y.

Example 4

A delaminatable release liner is prepared according to the method ofExample 1. During the lamination of the LDPE film to the TPO film a 1inch wide strip of 0.0.13 mm (0.5 mil) thick polymethylmethacrylate(PMMA) film is placed across the TPO film so that the LDPE extrudate andLDPE film are laminated over the PMMA strip. After lamination, the filmlaminate is rolled into a stock roll with the PMMA film stripapproximately 20 feet into the roll. The stock roll is optionally coatedon one or both sides with a release material (e.g., silicones ofExamples 2 and 3) and then laminated to a double coated tape to form atape stock roll. The tape stock roll is then slit into narrower, e.g., 1cm, rolls of approximately 20 feet in length. The section of the PMMAstrip on each roll forms a tab that may be used to start thedelamination of the polyethylene release layer during furtherprocessing.

Various modifications and alterations to this invention will becomeapparent to those skilled in the art without departing from the scopeand spirit of this invention. It should be understood that thisinvention is not intended to be unduly limited by the illustrativeembodiments and examples set forth herein and that such examples andembodiments are presented by way of example only with the scope of theinvention intended to be limited only by the claims set forth herein asfollows and equivalents thereof.

1. An adhesive tape assembly comprising: a double-sided adhesive tapecomprising front and back adhesive sides, each of said adhesive sidescomprising a pressure sensitive adhesive; a substrate, wherein saidfront adhesive side of said double-sided adhesive tape is permanentlybonded to a surface of said substrate; and a delaminatable release linerin contact with, bonded to and readily removable from said back adhesiveside of said double-sided adhesive tape, said delaminatable releaseliner comprising: a first major release surface on one side of saidrelease liner, a second major release surface on an opposite side ofsaid release liner, and a plane of weakness between said first andsecond major release surfaces, wherein said release liner can be readilydelaminated lengthwise along said plane of weakness, between said firstand second major release surfaces, so as to form a first delaminatedlayer and a second delaminated layer, with said first, delaminated layercomprising said first major release surface and a first back sidesurface opposite said first major release surface, and said seconddelaminated layer comprising said second major release surface and asecond back side surface opposite said second major release surface,wherein said second major release surface is in contact with, bonded toand readily removable from said back adhesive side, and said first majorrelease surface is exposed.
 2. The adhesive tape assembly as set forthin claim 1, wherein said release liner comprises a first backing layerand a second backing layer, which respectively form the firstdelaminated layer and the second delaminated layer when said releaseliner is delaminated along said plane of weakness, and said first andsecond backing layers are two separate layers that are bonded to andreadily removable from each other along respective back side surfaces.3. The adhesive tape assembly as set forth in claim 2, wherein saidrelease liner further comprises an intermediate bonding layer that bondstogether the back side surfaces of said backing layers.
 4. The adhesivetape assembly as set forth in claim 2, wherein the back side surfaces ofsaid backing layers are in direct contact with each other.
 5. Theadhesive tape assembly as set forth in claim 1, wherein said releaseliner further comprises: a first release layer having a first majorsurface defining said first major release surface; and a second releaselayer having a second major surface defining said second major releasesurface; wherein each of said first and second release layers comprisesa silicone, a fluorocarbon, a low adhesive backsize, or a blend orcombination thereof.
 6. The adhesive tape assembly as set forth in claim5, wherein each of said first and second release layers comprises asilicone release material.
 7. (canceled)
 8. The adhesive tape assemblyas set forth in claim 1, further comprising a tab bonded to said secondback side surface, said tab being operatively adapted to facilitateremoval of said second delaminated layer from said adhesive tape bypulling on said tab.
 9. (canceled)
 10. The adhesive tape assembly as setforth in claim 1, wherein said adhesive tape further comprises a foamcore with said front adhesive side and said back adhesive side formingopposite sides thereof.
 11. The adhesive tape assembly as set forth inclaim 1, wherein the pressure sensitive adhesive for at least one ofsaid adhesive sides is a high bond strength pressure sensitive adhesivethat exhibits a bond strength of greater than about 112 g/cm after beingbonded to a polyolefin surface and removed from the polyolefin surfaceat a removal rate of about 30 cm/min.
 12. The adhesive tape assembly asset forth in claim 1, wherein the pressure sensitive adhesive for atleast one of said adhesive sides is a high bond strength pressuresensitive adhesive that exhibits a bond strength of at least about 357g/cm, after being bonded to a low density polyethylene surface for atleast 24 hours: and removed therefrom at a removal rate of about 30cm/min.
 13. The adhesive tape assembly as set forth in claim 2, whereinsaid first backing layer has a first melting point, and said secondbacking layer has a second melting point, wherein said second meltingpoint is at least 10° C. (50° F.) greater than said first melting point.14. (canceled)
 15. The adhesive tape assembly as set forth in claim 13,wherein said first backing layer comprises at least one of a highdensity polyethylene, a medium density polyethylene, a low densitypolyethylene, a linear low density polyethylene, an ultra-low densitypolyethylene, a polypropylene, a copolyester, a thermoplasticpolyolefin, an ethylene vinyl acetate copolymer, and combinationsthereof; and said second backing layer comprises at least one of apolypropylene, a polyester, a thermoplastic polyolefin, a copolymer ofpolyethylene and polypropylene, a laminate of a thermoplastic polyolefinlayer and a polyethylene layer, and combinations thereof.
 16. Theadhesive tape assembly as set forth in claim 1, wherein said substrateis a body portion of a vehicle.
 17. The adhesive tape assembly as setforth in claim 16 in combination with a tab, wherein said release linerhas been partially delaminated lengthwise between said first and secondmajor release surfaces so as to partially form said first delaminatedlayer and said second delaminated layer, and said tab is bonded to saidsecond back side surface of said partially formed second delaminatedlayer so as to enable said second delaminated layer to be removed fromsaid adhesive tape by pulling on said tab.
 18. A method of applying adouble-sided pressure sensitive adhesive tape to one or more surfaces,said method comprising: providing an adhesive tape assembly comprising adouble-sided adhesive tape and a delaminatable release liner, thedouble-sided adhesive tape comprising front and back adhesive sides,each of said adhesive sides comprising a pressure sensitive adhesive,the delaminatable release liner being in contact with, bonded to andreadily removable from the back adhesive side of the double-sidedadhesive tape, and the delaminatable release liner comprising: a firstmajor release surface on one side of the release liner, a second majorrelease surface on an opposite side of the release liner, and a plane ofweakness between the first and second major release surfaces, whereinthe release liner can be readily delaminated lengthwise along the planeof weakness, between the first and second major release surfaces, so asto form a first delaminated layer and a second delaminated layer, withthe first delaminated layer comprising the first major release surfaceand a first back side surface opposite the first major release surface,and the second delaminated layer comprising the second major releasesurface and a second back side surface opposite the second major releasesurface, wherein the second major release surface is in contact with,bonded to and readily removable from the back adhesive side, and atleast a portion of the first major release surface is exposed; applyingthe front adhesive side of the adhesive tape to a first substrate; atleast partially forming the first delaminated layer and the seconddelaminated layer by delaminating the release liner along the plane ofweakness so as to at least partially separate the first delaminatedlayer from the second delaminated layer; and bonding a tab to the secondback side surface of the at least partially formed second delaminatedlayer, such that the second delaminated layer can be removed from thetape by pulling on the tab. 19-22. (canceled)
 23. An adhesive tapeassembly comprising: a double-sided adhesive tape comprising front andback adhesive sides, each of said adhesive sides comprising a pressuresensitive adhesive; and a delaminatable release liner in contact with,bonded to and readily removable from at least one of said adhesivesides, said delaminatable release liner comprising: a first majorrelease surface on an exposed side of said release liner, a second majorrelease surface on an opposite side of said release liner, and a planeof weakness between said first and second major release surfaces,wherein said release liner can be readily delaminated lengthwise alongsaid plane of weakness, between said first and second major releasesurfaces, so as to form a first delaminated layer and a seconddelaminated layer, with said first delaminated layer comprising saidfirst major release surface and a first back side surface opposite saidfirst major release surface, and said second delaminated layercomprising said second major release surface and a second back sidesurface opposite said second major release surface, wherein saidadhesive tape assembly has (i) a first bond strength between said firstback side surface and said second back side surface, and (iii) a secondbond strength between said first major release surface and said frontadhesive side, and wherein said second bond strength is lower than saidfirst bond strength.
 24. The adhesive tape assembly as set forth inclaim 23, wherein said adhesive tape assembly has a third bond strengthbetween said second major release surface and said back adhesive side,and wherein said first bond strength is lower than said third bondstrength.
 25. The adhesive tape assembly as set forth in claim 23,wherein said release liner comprises a first backing layer and a secondbacking layer, which respectively form the first delaminated layer andthe second delaminated layer when said release liner is delaminatedalong said plane of weakness, said first and second backing layers aretwo layers that are bonded to and readily removable from each otheralong respective back side surfaces, said first backing layer comprisesa low density polyethylene, and said second backing layer comprises athermoplastic polyolefin having three distinct layers, with said threedistinct layers comprising first and second clear outer layers, and anintermediate layer containing a colorant positioned between said: firstand second clear outer layers.
 26. The adhesive tape assembly as setforth in claim 23, wherein said first release layer comprises anepoxy-functional polydimethylsiloxane polymer, an epoxy-functionallinear polydimethylsiloxane copolymer, of a combination thereof; andsaid second release layer comprises a silanol terminatedpolydimethylsiloxane resin.
 27. A roll of adhesive tape comprising theadhesive tape assembly as set forth in claim 23.